Tehran is a city of nine million people, with 17 million in the larger metropolitan area.

Saturday is the first day of the week for Iranians.

Millions of people are at work, and children are in school.

世界は複雑で、わからないことだらけだ。わかろうとする努力を続けつつ、それでも、"わからないということ"に慣れることも必要だ。